// 指针 交换
#include <stdio.h>

void my_swap(int *a, int *b)
{

    int tmp = *a;
    *a = *b;
    *b = tmp;

    return;
}

int main(int argc, char **argv)
{
    int a = 10;
    int b = 20;

    printf("%d %d\n", a, b);

    my_swap(&a, &b);

    printf("%d %d\n", a, b);
    return 0;
}